Bell wrote an essay for TIME on Tuesday, in which she opened up about her own experiences with depression. Her story is a raw, honest testimony to the struggles people with mental health conditions face on a regular basis.

"For me, depression is not sadness. It’s not having a bad day and needing a hug," she wrote. "It gave me a complete and utter sense of isolation and loneliness ... I felt worthless, like I had nothing to offer, like I was a failure. Now, after seeking help, I can see that those thoughts, of course, couldn’t have been more wrong."

The "Frozen" star also called out society's lack of compassion or understanding when it comes to mental health issues, driving home the point that mental health disorders don't discriminate based on gender, age or even celebrity.

"There is such an extreme stigma about mental health issues, and I can’t make heads or tails of why it exists," she continued. "Anxiety and depression are impervious to accolades or achievements. Anyone can be affected, despite their level of success or their place on the food chain."

Bell's advocacy for mental health has been strong lately. Last month, the actress sat down for an interview for "Off Camera with Sam Jones," where she discussed her depression and anxiety issues. She slammed the negative perceptions surrounding treatment, and especially medication.

“If you do decide to go on a prescription to help yourself, understand that the world wants to shame you for that, but in the medical community, you would never deny a diabetic his insulin. Ever,” she said in the interview. “But for some reason, when someone needs a serotonin [reuptake] inhibitor, they’re immediately crazy or something.”

Nearly one in five Americans will experience a mental health issue at some point in their life, yet many people don't seek treatment for these issues due to stigma. Candid, public conversations like Bell's help to eradicate a negative stereotype that has no sense of existing in the first place.

"Depression is a problem that actually has so many solutions," Bell wrote in TIME. "Let’s work together to find those solutions for each other and cast some light on a dark situation."